以下实例演示了如何通过继承 Thread 类并使用 isAlive() 方法来检测一个线程是否存活：
public class TwoThreadAlive extends Thread {
public void run() {
for (int i = 0; i < 10; i++) {
printMsg();
}
}
public void printMsg() {
Thread t = Thread.currentThread();
String name = t.getName();
System.out.println("name=" + name);
}
public static void main(String[] args) {
TwoThreadAlive tt = new TwoThreadAlive();
tt.setName("Thread");
System.out.println("before start(), tt.isAlive()=" + tt.isAlive());
tt.start();
System.out.println("just after start(), tt.isAlive()=" + tt.isAlive());
for (int i = 0; i < 10; i++) {
tt.printMsg();
}
System.out.println("The end of main(), tt.isAlive()=" + tt.isAlive());
}
}以上代码运行输出结果为：
before start(), tt.isAlive()=false just after start(), tt.isAlive()=true name=main name=Thread name=main name=main name=main name=main name=main name=main name=main name=main name=main name=Thread name=Thread name=Thread name=Thread name=Thread The end of main(), tt.isAlive()=true name=Thread name=Thread name=Thread name=Thread